Curved slide fastener chain and method for producing curved slide fastener

Abstract

A curved slide fastener chain and a method for producing a curved slide fastener are disclosed. The curved slide fastener chain comprises a pair of fastener tapes and a plurality of fastener element rows planted on each of a pair of the fastener tapes. Each of the element rows includes a straight and a curved inter-engagement portion. The curved inter-engagement portions are dis-inter-engaged while the straight inter-engagement portions are inter-engaged, so that each of the pair of fastener tapes are able to extend in a straight line. Therefore, deformation of the curved inter-engagement portions due to heat and tension applied thereto during the washing, dewatering and drying steps in producing a curved slide fastener can be prevented.

I claim: 
     
       1. A method for producing a curved slide fastener including a pair of element rows each having straight and curved inter-engagement portions comprising the steps of: forming fastener stringers by planting a plurality of element rows of a predetermined length on each of the fastener tapes of the fastener stringers in series and spaced relation;   inter-engaging a pair of fastener stringers to form a fastener chain;   washing and dewatering said fastener chain and drying the same while applying tension thereto;   finishing said fastener chain to form slide fasteners by cutting said slide fastener chain into a unit length after applying parts, such as sliders, to said fastener chain;   characterized in that: (a) in the step of forming fastener stringers, a pair of fastener stringers are so formed simultaneously that the fastener elements constituting straight and curved inter-engagement portions are planted on each of the inner side edges of said fastener tapes with the element pitch in the curved inter-engagement portion of one of the pair of fastener stringers being larger than the element pitch in the curved inter-engagement portion of the other of the pair of fastener stringers;   (b) in the step of inter-engaging the pair of fastener stringers, the pair of fastener stringers are inter-engaged to form a fastener chain in which at least most of said curved inter-engagement portions are dis-inter-engaged; and   (c) in the step of washing, dewatering and drying the fastener chain, said fastener chain is processed with the curved inter-engagement portions being at least party not inter-engaged.